Особенности эволюции химического состава фосфатов как отражение многофазного становления щелочно-карбонатитовой флюидо-эксплозивной системы Среднего Тимана

he alkaline-carbonate fluid-explosive structure in the Middle Timan includes carbonatites, carbonatized fluidexplosive dikes, and fenitized terrigenous-carbonate rocks of the Riphean. Phosphates, represented by monazite and apatite, are formed in all rocks. The chemical composition of the minerals testifies to the multiphase formation of this structure and a single source of fluids involved in its formation.В щелочно-карбонатитовую флюидо-эксплозивную систему на Среднем Тимане входят карбонатиты, карбонатизированные флюидо-экспозивные дайки и фенитизированные терригено-карбонатные породы рифея. Во всех породах кристаллизуются фосфаты, представленные монацитом и апатитом. Химический состав минералов свидетельствует о многофазности становления данной системы и едином источнике флюидов, участвовавших в ее формировании

Обобщенный опыт изучения и диагностики конвергентных пород на примере карбонатизированных флюидоэксплозивных ультрамафитов дайкового комплекса Среднего Тимана

Fluid-explosive rocks of the dike complex are identified in the Middle Timan. The rocks have convergent properties due to a combination of explosive and metasomatic processes. The study of the petrographic features of the rocks revealed their explosive nature. Further study of the chemical composition of rock-forming minerals established the source of the mantle material and the paragenetic relationship with carbonatite magmatism. The fluid-explosive rocks of the dyke complex have a long-term multistage formation history. The fluids caused fenitization of the host strata and its disintegration. Solid-gas material of the mantle-crustal compound fills the cracks. At the last stage of formation of fluid-explosive rocks, the rare-metal, rare-earth, and sulfide mineralization took place.На Среднем Тимане выделены дайковые флюидоэксплозивные породы с конвергентными свойствами за счет сочетания эксплозивных и метасоматических процессов. Изучение петрографических особенностей пород выявило их эксплозивную природу, а исследование химического состава породообразующих минералов установило источник мантийного материала и парагенетическую связь с карбонатитовым магматизмом. Флюидоэксплозивные породы дайкового комплекса связаны с фенитизацией вмещающей толщи с последующей ее дезинтеграцией и заполнением трещин твердогазовым материалом смешанного мантийно-корового состава. На последнем этапе становления флюидоэксплозивных пород за счет карбонатизации проявляются редкометалльно-редкоземельная и сульфидная минерализации

Feynman Diagrams and Differential Equations

We review in a pedagogical way the method of differential equations for the evaluation of D-dimensionally regulated Feynman integrals. After dealing with the general features of the technique, we discuss its application in the context of one- and two-loop corrections to the photon propagator in QED, by computing the Vacuum Polarization tensor exactly in D. Finally, we treat two cases of less trivial differential equations, respectively associated to a two-loop three-point, and a four-loop two-point integral. These two examples are the playgrounds for showing more technical aspects about: Laurent expansion of the differential equations in D (around D=4); the choice of the boundary conditions; and the link among differential and difference equations for Feynman integrals.Comment: invited review article from Int. J. Mod. Phys.

Use of open electronic courses in educational activity

The use of open electronic courses is a relatively new tendency in education and it is not yet fully discovered by researchers. With its introduction a change in the structure of the educational system happens. Therefore, the article studies the specifics of the introduction of online courses, including requirements to them, as well as factors that slow down their active development. Due to it, the following methods of investigation were used as: analysis, synthesis, deduction, induction. As an example, Kozma Minin Nizhny Novgorod State Pedagogical University - Minin University was used. Based on the study of the "Regulations on the use of open courses in the educational activities of Minin University", it was noted, in addition to the functions of the coordination group on open education, that for the trainee at the end of the course, in the case of unsatisfactory result, the possibility of the recalculation is established. This paragraph is used not by every university. In the article we make a conclusion that open courses are a new qualitative step in the development of world education, but online courses would be much more effective as narrow-minded, adult-oriented, and deeply motivated for learning. Taken as the basis of research, Minin University showed that the university is ready for the implementation of online courses. It is one of the few universities that actively use open courses in Russia.peer-reviewe

Нейропротективное действие хлорида лития на модели остановки сердца у крыс

Lithium chloride, which is used for the treatment of bipolar disorders, has a neuroprotective effect in conditions associated with acute and chronic circulatory disorders.The purpose of the study: to investigate the efficacy of lithium chloride for the prevention of post-resuscitation death of hippocampal neurons during the post-resuscitation period.Material and methods. Cardiac arrest for 10 minutes was evoked in mature male rats by intrathoracic clumping of the vascular bundle of the heart, followed by resuscitation. 40 mg/kg or 20 mg/kg of 4,2% lithium chloride (LiCl) was injected intraperitoneally 1 hour before cardiac arrest, on the 1st and 2nd day after resuscitation (n=9). Untreated animals received equivalent doses of saline (n=9). Rats after a sham surgery served as a reference group (n=10). The number of viable neurons in the CA1 and CA3/CA4 fields of the hippocampus was estimated in slides stained with cresyl violet by day 6 or 7 postresuscitation. In a separate series of experiments, at the same terms, we studied the effect of lithium chloride on the protein content of GSK3β (glycogen synthase kinase) in brain tissue using Western-Blot analysis.Results. Histological assay showed that a 10-minute cardiac arrest resulted in a decrease in the number of viable neurons in the hippocampal CA1 field — by 37.5% (P0.001), in the CA3/CA4 field — by 12.9% (P0.05) vs. the reference group. Lithium treatment increased the number of viable neurons in resuscitated rats — in the CA1 field by 37% (P<0.01), in the CA3/CA4 field — by 11.5% (P0.1) vs. the untreated animals. It was found that lithium caused an increase in phosphorylated form of GSK3β: by 180% vs. the reference group (P[1]0.05), and by 150% vs. the untreated animals (P0.05).Conclusion. Lithium treatment leads to a pronounced neuroprotection in the neuronal populations of the hippocampus post-resuscitation. This effect may be due to an increase in the content of the phosphorylated form of GSK3β protein. The results indicate a high potential of lithium for the prevention and treatment of neurodegenerative disorders caused by a temporary arrest of blood circulation. Хлорид лития, используемый для коррекции биполярных расстройств, обладает нейропротективным эффектом при состояниях, связанных с острым и хроническим нарушением кровообращения в головном мозге. Цель исследования — оценить эффективность хлорида лития для предотвращения гибели высокочувствительных к гипоксии нейронов гиппокампа в постреанимационном периоде после временной остановки сердца. Материал и методы. Остановку сердца у взрослых крыс-самцов на 10 минут вызывали путем внутриторакального пережатия сосудистого пучка сердца с последующей реанимацией. 9-ти животным вводили раствор 4,2% LiCl за 1 час до остановки сердца (40 мг/кг в/б), на 1-е и на 2-е сутки после реанимации (20 мг/кг в/б, соответственно). 9 нелеченых животных в те же сроки получали эквивалентные дозы физиологического раствора хлорида натрия. Контролем служили ложноперированные крысы (n=10). Через 7 дней методом морфометрического анализа оценили число жизнеспособных нейронов в полях СА1 и СА3/СА4 гиппокампа на срезах, окрашенных крезиловым фиолетовым по Нисслю. В отдельной серии экспериментов с помощью Western-Blot анализа в эти же сроки исследовали влияние хлорида лития на содержание белка GSK3β (киназа гликогенсинтазы киназы-3) в ткани мозга. Результаты. При гистологическом исследовании установили, что 10-минутная остановка сердца приводит к снижению числа жизнеспособных нейронов в поле СА1 гиппокампа — на 37,5% (p0,001), в поле СА3/СА4 — на 12,9% (p0,05). Применение LiCl приводило к увеличению числа жизнеспособных нейронов гиппокампа у реанимированных крыс в поле СА1 на 37% (p0,01), в поле СА3/СА4 — на 11,5% (p0,1) по сравнению с нелечеными животными.  При исследовании белка GSK3β установили, что у реанимированных животных, получавших хлорид лития, содержание его фосфорилированной формы в ткани мозга было выше на 180% по сравнению с контролем (р0,05), и на 150% выше, чем у нелеченных животных (р0,05). Заключение. Введение хлорида лития в постреанимационном периоде приводило к выраженной нейропротекции в нейрональных популяциях гиппокампа. Этот эффект может быть обусловлен повышением содержания фосфорилированной формы белка GSK3β. Полученные результаты свидетельствуют о высоком потенциале лития для профилактики и лечения нейродегенеративных нарушений, вызванных временной остановкой кровообращения.

Experience in the use of docosahexaenoic acid (BrudiPlus) in patients with increased sperm DNA fragmentation index in Acad. V.I. Kulakov Research Center for Obstetrics, Gynecology and Perinatology

Male factor is the reason of infertility in almost half of marriages. Infertile men have the percentage of sperm with violations of DNA integrity of over 30 %; with that, healthy fertile men have that indicator of less than 15 %. Understanding of importance of damages of sperm DNA is growing with distribution ofauxiliary reproductive technologies. As of today, these consequences have not been studies yet, and the therapeutic effect of intake of antioxidants has not direct correlation with the sperm DNA fragmentation level. Docosahexaenoic acid is one of the most valuable omega-3 polyunsaturated fatty acids for human health. Docosahexaenoic acid is the main component of the brain gray matter, retina, testes, and sperm cell membranes. In connection with that, a study was held the purpose of which was to assess the effect of the nutraceutical enzymatic docosahexaenoic acid triglyceride (BrudiPlus) in high concentrations on damaged sperm DNA of patients with idiopathic pathozoospermia. 40 patients with idiopathic pathozoospermia and the level of DNA fragmentation over the statutory value took part in this study. The following positive results were received: intake of BrudiPlus allowed decreasing sperm DNA damages and improving of antioxidant system of sperm

Long-term field and laboratory leaching tests of cemented radioactive wastes

Experiments with real and simulated radioactive cementitious wasteforms were set up to compare the leaching behaviour of cementitious wasteforms containing nuclear power plant operational waste in field and laboratory test conditions. Experiments revealed that the average annual Cs-137 leach rate in deionised water was about thirty-five times greater compared with the measured average value for the 1st year of the field test. Cumulative leached fraction of Cs-137 for 1st year (3.74%) was close to values reported in literature for similar laboratory experiments in deionised water, however more than two orders of magnitude higher than the 1st year leached fraction of Cs-137 in the repository test (0.01%). Therefore, to compare field and laboratory test results, a scaling factor is required in order to account for surface to volume factor difference, multiplied by a temperature factor and a leach rate decrease coefficient related to the ground water composition. (C) 2011 Elsevier B.V. All rights reserved

Threshold J/ψ−J/\psi- production in nucleon-nucleon collisions

We analyze $J/\psi-$ production in nucleon-nucleon collisions near threshold in the framework of a general model independent formalism, which can be applied to any reaction $N+N\to N+N+V^0$, where $V^0=\omega$, $\phi$, or $J/\psi$. Such reactions show large isotopic effects: a large difference for $pp$- and $pn$-collisions, which is due to the different spin structure of the corresponding matrix elements. The analysis of the spin structure and of the polarization observables is based on symmetry properties of the strong interaction. Using existing experimental data on the different decays of $J/\psi-$meson, we suggest a model for $N+N\to N+N+J/\psi$, based on $t-$channel $\eta+\pi$-exchanges. We predict polarization phenomena for the $n+p\to n+p+J/\psi$-reaction and the ratio of cross sections for $np$ and $pp$-collisions. For the processes $\eta(\pi)+N\to N+J/\psi$ we apply two different approaches: vector meson exchange and local four-particle interaction. In both cases we find larger $J/\psi$-production in $np$-collisions, with respect to $pp$-collisions.Comment: 17 pages, 6 figure